Horizontal boiler having a fire tube and smoke tubes



April 1965 M. c. KuczEwsKl DE PORAY 3,176,663

HORIZONTAL BOILER HAVING A FIRE TUBE AND SMOKE TUBES Filed Sept. 7, 1962 United States Patent 4 Claims. a. 122-149 The object of the present invention is to provide a horizontally elongated boiler having a main horizontally extending fire tube which is eccentric relative to the longitudinal axis of the shell and a nest of smoke tubes, said fire tube and smoke tubes extending between a forward tube plate and a rear tube plate, the rear plate being disposed at the outlet end of the fire tube.

In said boiler, a substantially vertical longitudinally extending partition is secured to the bottom portion of the shell and connects the two tube plates, said partition wall longitudinally dividing the immersed part of the boiler into a fire tube zone surrounding the fire tube and devoid of smoke tubes and a lateral zone containing the nest of smoke tubes. The fire tube has a constricted neck portion provided with a refractory lining interposed between the outlet of the fire tube and the adjacent rear tube plate so as to facilitate the downward circulation of the water in the part of the fire tube zone around the neck portion.

Further features and advantages of the invention will become apparent from the following specification, with reference to the accompanying drawing to which the invention is in no way limited.

In the drawing:

FIG. 1 is a longitudinal sectional view taken along line 1--1 of FIG. 2 of a boiler embodying the invention;

FIG. 2 is a transverse cross-sectional view taken along line 22 of FIG. 1, and

FIG. 3 is a fragmentary sectional view, on an enlarged scale, of a detail of the invention.

In the illustrated embodiment, the boiler comprises a body formed by a conventional horizontally elongated cylindrical shell 1 resting on a support 2. In an eccentric position with respect to the axis of the shell 1 there is, a horizontal longitudinally extending fire tube 3. The fire tube 3 is provided at its forward end with a refractory throat 4 to which there is fitted a burner BR using liquid or other suitable fuel.

The fire tube 3 has at its rear end a constricted neck portion 5 which operates as an expansion element. The neck portion 5 is lined with a refractory lining 6 which constitutes a secondary furnace, the lining 6 being of the type described in French Patent No. 1,033,311.

The fire tube 3 communicates by way of the throat 7 of lining 6 with a rear smoke box 8 defined by a tube plate 8a, and a rear end Wall 8b. Smoke tubes 9, extending longitudinally of the shell 1, communicate between the rear smoke box 8 and a forward smoke box 10 defined by a forward tube plate 10a and a forward end wall 10b. These tubes are of the one-pass type since they are so disposed that the gases travel through a single path in the boiler (from the rear to the forward end in the presently-described boiler). The forward smoke box 10 communicates through the medium of its lower portion with a longitudinal duct or flue ll disposed laterally against a lower portion 1a of the body 1, one wall of the duct 11 being formed by a portion of the shell 1 below the smoke tubes 9. The duct 11 exends along the entire length of the shell, and at the rear communicates with a connection 12 for connecting to a chimney stack.

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The nest 9 of smoke tubes lies above and below the horizontal plane )OC. The plane XX, which contains the longitudinal axis of the fire tube 3, divides the smoke tubes 9 into an upper nest 9a termed the vaporisation nest and a lower nest 9b termed the heating nest.

The boiler further comprises a system of battles or partition walls connected to the wall of the body namely: a cylindrically arcuate wall 13, termed a circulator, which is co-axial with the shell 1 and is spaced from and secured along the shell 1 throughout the height of the upper nest 9a; a horizontal bafile 14, termed deflector, which is disposed and secured along the entire length of the shell 1 at the lower level of the upper nest, that is, approximately in the plane XX; and a vertical partition wall 15 (which can be of insulating type) which is disposed and secured along the entire length of the shell 1 and extends vertically alongside the nest between the latter and the fire tube at the height between the plane XX and the line on which said partition wall joins the shell 1.

It can be seen that this structure divides the immersed part of the boiler into a zone A surrounding the fire tube and devoid of smoke tubes and a lateral zone B which contains the nest of smoke tubes; said zone B being itself divided by the deflector 14 into a lower chamber or heating chamber C and an upper or vaporisation chamber D, these two chambers respectively containing the lower part 9b and the upper part 9a of the nest of smoke tubes. V

A feed water inlet 16 communicates with the chamber C.

The boiler according to the invention also has the following features.

A closed tube 17 (FIGS. 2 and 3) is axially disposed in each of the smoke tubes so as to constitute for the passage of the gases an annular section over the entire length, or at the end, of their path in the smoke tubes. These bodies 17, which are termed accelerators, are supported within the tubes by star-shaped supports 17a which leave the major part of said annular section free.

At the entrance of each smoke tube a small nozzle 18 supplying steam or air under pressure connected to a manifold 19 permits, when a valve (not shown) accessible from outside the boiler is opened, cleaning the smoke tubes from time to time.

The boiler operates in the following manner:

The products of combustion at high temperature travel through the fire tube and then through the throat 7, the refractory lining 6 of which operates, at high temperature, as a secondary furnace which homogenizes the combustion products by turbulence and by activating the combustion reactions. The hot gases at the outlet of the secondary furnace enter the smoke box 8 whence they enter the smoke tubes 9 through which they travel at high speed, the cross-section area being reduced by the presence of the accelerators 17, causing the speed at which these gases pass through this section to be accelerated, which increases the rate of heat transmission.

The smoke tubes 9 and accelerators 17 may be maintained in a clean state by means of the nozzles 18. This cleaning is particularly effective since it can be carried out during boiler operation in the direction of flow of the bases; it permits maintaining the tubes clean, particularly in the small annular section, and thus maintaining efiicient heat transmission.

The gases, after having passed through the forward smoke box 10, enter the outlet duct or flue 11 through which they pass before entering the chimney connection Within the shell 1, the waterdescends freely in the space between the circulator 13 and the shell 1, then arvaeos modifies its path when the deflector 14 is encountered, and travels along a substantially horizontal path which returns it to the vaporization nest 9a so as to replace the steam-water emulsion which rises through this nest.

Owing .to the deflector 14, the hot water, which thus circulates. in a path such as c, cannot affect the lower nest. In this Way, there is obtained an accelerated circulation transversely through the vaporisation nest 9a, which provides an improved heat exchange, and also reduces the tendency of mud or fur to accumulate on the tubes and this affords a protection of the. tubes against dangerous overheating.

In the lower smoke tube chamber C which is laterally separated from the rest of the boiler by the partition wall 15 and the deflector 14, the cold feed water supply entering at 16, before being mixed with the hot water, cools the smoke tubes utilizing the difference between the temperature of the feed water and that of the smoke which temperature difference is maximum and improves the efficiency of heat transmission. 7

The fire tube 3 is actively cooled by a rapid circulation of water around this fire tube, owing to the complete absence of smoke tubes in the zone A in its upper part E and in its lower part F and lateral par-ts G and H.

The presence of the refractory collar 6,-whic-h constitutes a heat insulator, prevents the vaporisation of the water, around the constricted neck portion 5 and consequently the water can freely descend around the neck portion. the neck portion 5 leaves a correspondingly increased free area for the circulation of the descending water.

The water thus travels through a path of free circulation indicated by the arrows to f (FIG. 1) passing actively along the fire tube 3 and thus affording protection against a dangerous overheating of this element which works at a very high rate of'heat exchange.

It Will be observed that the portion 1a of the shell 1 below the smoke tubes 9 forms one wall of the duct 11. The duct 11 carries smoke which transfers part of its heat to the shell 1 before escaping through the chimney connection 12. This heat is transferred to the surface 1a, which is subjected to a great water-smoke Moreover, the small transverse area of said shell and terminating with its top located below said axis; a fire tube extending between said front wall and said rear tube plate eccentrically with respect to said axis at one side of said partition, said fire tube having a constricted neck portion in proximity to said rear tube plate and communicating with said rear smoke box; burner means adjacent to said front wall for projecting a flame into said fire tube; a refractory lining in said neck portion, said lining thermally insulating said neck portion for reducing the operating temperature thereof; a nest of laterally spaced smoke tubes of diameters smaller than said fire tube extending parallel to the longitudinal axis of said shell and between said tube plates, said smoke tubes being located at the other side of said partition in a space which extends vertically both above and below the top of said partition; inlet means at said other side of said partition for introducing feed water into said shell intermediate said tube plates and below said smoke tubes, said water extending upwardlyabove and laterally surrounding all of said tubes; and means for connecting said front smoke box to a chimney.

2. A boiler according to claim 1, further comprising manifold means in said rear smoke box; and a plurality of nozzles connected to said manifold means, each nozzle temperature difference which provides excellent conditions for the efiicient removal of heat from the smoke.

Although a specific embodiment of the invention has been shown and described, many modifications and changes may be made therein without departing from the scope of the invention as defined in the appended claims.

Having now described my, invention What I claimas new and desire to secure by Letters Patent is:

1. A boiler comprising a horizontally elongated cylindrical shell; front and rear walls closing the ends of said shell; a forward tube plate extending transversely of said shell, said forward plate and said front Wall de-- fining a forward smoke box therebetween; a rear tube plate extending'transversely of said shell, said rear plate and rear wall defining a rear smoke box therebetween; a vertical partition extending upwardly from the bottom portion of said shell and between said tube plates, said partition extending parallel to the longitudinal axis of being directed axially into one end of one of said smoke tubes and being spaced therefrom to permit the free flow of combustion gases into said one end, whereby pressure fluid may be supplied to said manifold for cleaning said smoke tubes while operation of said boiler continues.

3. A boiler according to claim 1, further comprising a duct, one wall of which is formed by a portion of said shell located below said smoke tubes at said other side of said partition, said duct being included in said means for connecting said frontsmoke box to a chimney.

4. A boiler according to claim 1, further comprising bafile means extending axially of said shell between said tube plates, said baffle means being located above said partition at said other side thereof, said. bafiie means being positioned between said smoke tubes and said shell, said baffle means directing Water heated by the. upper ones of said smoke tubes transversely therebetween and over said partition toward saidfire tube.

References Cited by the Examiner UNITED STATES PATENTS 774,832 11/04 Copeland 122-410 1,672,617 6/28 Lasker .122501 1,874,452 8/32 Cole 122391 FOREIGN PATENTS 1,190,803 4/59 France.

637,281 5/50 Great Britain.

OTHER REFERENCES Palamede No. 39, Eollettino Della Prevantive Industriali, Part 1, vol. 6, Series 2 Tavola IX of 1875.

PERCY L. PATRICK, Primary Examiner.

FREDERICK L. MA'IT'ESON, 111,, Examiner. 

1. A BOILER COMPRISING A HORIZONTALLY ELONGATED CYLINDRICAL SHELL; FRONT AND REAR WALLS CLOSING THE ENDS OF SAID SHELL; A FORWARD TUBE PLATE EXTENDING TRANSVERSELY OF SAID SHELL, SAID FORWARD PLATE AND SAID FRONT WALL DEFINING A FORWARD SMOKE BOX THEREBETWEEN; A REAR TUBE PLATE EXTENDING TRANSVERSELY OF SAID SHELL, SAID REAR PLATE AND REAR WALL DEFINING A REAR SMOKE BOX THEREBETWEEN; A VERTICAL PARTITION EXTENDING UPWARDLY FROM THE BOTTOM PORTION OF SAID SHELL AND BETWEEN SAID TUBE PLATES, SAID PARTITION EXTENDING PARALLEL TO THE LONGITUDINAL AXIS OF SAID SHELL AND TERMINATING WITH ITS TOP LOCATED BELOW SAID AXIS; A FIRE TUBE EXTENDING BETWEEN SAID FRONT WALL AND SAID REAR TUBE PLATE ECCENTRICALLY WITH RESPECT TO SAID AXIS AT ONE SIDE OF SAID PARTION, SAID FIRE TUBE HAVING A CONSTRICTED NECK PORTION IN PROXIMITY TO SAID REAR TUBE PLATE AND COMMUNICATING WITH SAID REAR SMOKE BOX 